The present invention relates to a child seat energy management restraint anchor device for use in connection with a child seat that is secured to a vehicle seat and, more particularly, to an improved restraint device or system that manages the load and displacement characteristics of one or more child seat anchors upon experiencing a vehicle impact condition or a predetermined change in acceleration.
Child safety seats are routinely secured to the seat of a vehicle through conventional methods and use of such equipment as a standard vehicle seat belt and child seat attachment hardware such as tethers or straps that are generally included with, or integral to, the child seat assembly. The tethers or straps have hooks, clips, clasps and/or rigid, quick release engagement clip or claw-like mechanisms at their ends to engage the vehicle seat anchors. Standard systems routinely utilize child seat straps with quick release mechanisms for directly engaging the vehicle anchors, or a conventional child seat tether/strap or belt assembly wherein the seat belt and/or child tether/strap webbing is intertwined through brackets or guide apertures in the child seat, so that the child seat may be drawn against the vehicle seat and secured to the vehicle seats lower restraint anchors. Additionally, a top tether incorporating a tether hook, clip or clasp also engages a vehicle anchor to further secure the upper portion of the child seat to the vehicle seat. Child safety seats generally move in a car-forward direction, relative to the vehicle seat, during an abrupt vehicle deceleration or dynamic frontal vehicle impact event, causing a resulting inertial force to be impinged on the points of contact between the child seat attachment hardware and the interfacing vehicle restraint anchors. The effects of such inertial forces can be significant and thus management of these forces can be helpful to reduce the loads transferred to the seated child occupant.
It is therefore desirable to reduce occupant injury in child seats by providing an energy management restraint anchor device that enhances the functional relationship between the child seat and the controlled, common points of engagement with the vehicle interior environment, in order to manage the displacement of a child seat, and the corresponding energy transferred to the child occupant, as the result of an abrupt vehicle deceleration or vehicle impact event. This may be achieved by controlling the translation and rotation of a child seat that is engaged with a vehicle's restraint anchors, subjected to the aforementioned conditions. One or more load bearing deformable energy absorbing elements are incorporated in each energy management restraint anchor device, or each shared energy management restraint anchor system. The deformable elements are configured to be distorted and/or displaced when subjected to predetermined restraint anchor input load conditions, thereby absorbing and redistributing restraint energy and permitting corresponding restraint anchor extraction. Incorporation of one or more load bearing deformable members that may, when combined together or incorporated individually, exhibit a variety of material properties, cross-sectional geometries, and correspondingly unique resultant energy absorption characteristics, enhances the ability to tune the load redistribution and anchor displacement capabilities of the energy management restraint device. A wide variety of energy management characterization profiles may therefore be derived for a given restraint anchor, or combination of anchorages associated with an energy management restraint device or system, including progressive, digressive, multi-level and variable rise rate load limiting that may be achieved over a variety of predetermined anchor displacement values, thereby enabling customized load carrying and load redistribution characteristics for various occupant sizes or occupant loading conditions.
Additionally, in markets such as the United States, FMVSS 225 regulations provide specific quasi-static load carrying capacity and displacement requirements, applicable to lower anchors. Accordingly, there is a need to provide a lower restraint anchor device or system uniquely capable of permitting dynamic anchor displacement and corresponding energy management without permitting excessive anchor deformation or displacement under quasi-static loading conditions, in order to meet lower anchorage static load requirements of FMVSS 225. This may be achieved by incorporating dynamic energy management and anchor displacement control interlock features, in association with an energy management restraint anchor device or system, operable to prevent or restrict dynamic anchor movement under quasi-static conditions, thereby providing restraint anchor performance characteristics comparable to that of traditional fixed position anchors known in the art. Such displacement control features are further operable to release an anchor from a constrained position in order to facilitate dynamic restraint energy management functionality. The interlocking controls may be activated by way of inertial forces impinging upon them, or by an electrical signal controlling the interlocking component engagement relationship, in order to facilitate the appropriate energy management and anchor displacement functionality.
It is also desirable to provide an energy management anchorage device or system that facilitates retraction of a deployed restraint anchor after having at least partially deformed the energy absorption material(s), to aid in re-coupling the rebounding child seat with the vehicle seat as the rate of vehicle deceleration decreases. Refraction may occur unassisted as the child seat rebounds to re-engage the vehicle seat, or retraction may be facilitated mechanically by incorporating one or more anchor biasing return assist members, operable to aid in returning the displaced anchor towards a pre-deployed position. Anchor assist members may be spring biased. Refraction may be achieved as a result of an electronic signal provided to activate a variety of mechanical, electromagnetic, actuator driven or motorized retraction features or mechanisms associated with an energy management device restraint anchor.
It is further desirable to provide various interlocks for controlling the displacement of an energy management restraint device anchor at various phases of device operation. A variety of interlocking engagement conditions are described relative to controlling the movement of said anchor. An interlock may be employed to retain an anchor in a first un-deployed position, or to limit the rate, or total amount, of anchor displacement permitted in combination with the distortion of at least one deformable material member. An interlock may be operable to preclude anchor displacement in an unloaded condition or under quasi-static load conditions, and may release or restrain an anchor when the energy management device experiences a predetermined change in inertial acceleration. An interlock may also be employed to either temporarily or permanently fix the position of an extracted or refracted anchor, or to prevent or permit secondary extraction of an anchor under predetermined conditions. An interlock may be provided to fix the position of an anchor in an intermediate position, relative to a fully extracted or refracted position. An inertial interlock may be engaged or disengaged as the result of a change in position of a mechanically articulating member having a biased mass portion, or that may be spring biased. An interlock may also be represented by magnetic, motorized, solenoid or similar actuator driven components operable to the control movement of a restraint anchor, wherein said actuator receives a control signal derived from identification of a predetermined device state change, detected by an electronic or mechanical sensor.
It is desirable to provide an improved energy management anchorage device or system that interfaces with the child seat attachment hardware and may be mounted to a structural or load bearing member of the vehicle seat, package tray, roof, floor, or any other desired location as permitted by law.
The present invention includes a dynamic displacement energy management anchorage device or system for use with at least one vehicle child seat. The device or system may include one or more of the following—a retainer or housing; an anchor; a fixed-position or moveable load bearing member relative to which at least one load bearing deformable energy absorption member may be positioned or react against; a connecting member generally interfacing with a load bearing member and an anchor or anchor end; an element for biasing the position of an anchor, facilitating anchor retraction during rebound or supplement the recovery of a resilient deformable material; at least one interlock configurable to control the position of said anchor under one or more operating conditions; an indicator for signaling one or more states of device function.
Further areas of applicability and functional characteristics of the present invention will become apparent from the detailed description provided herein. It should be understood that the detailed description and specific examples, while indicating preferred embodiments of the present invention, are intended for purposes of illustration only, and various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. It will be appreciated that the present invention can be utilized in automotive, aerospace, nautical, amusement or alternative land-based personal or commercial vehicle or cargo transportation applications where it is desirable to manage the displacement of a child seat anchorage, an occupant secured to an anchorage, or where other transportable items may need to be tethered to anchorages.